1. Field of the Invention
This invention relates to millimeter wave imaging systems, and more specifically to ground based millimeter wave imaging systems.
2. Backpround and Material Information
Millimeter wave imaging systems are used to aid aircraft in landing during poor visibility conditions (e.g., fog, rain . . .). Current millimeter wave imaging systems used for landing aircraft generally employ an active transceiver and a corresponding image processor that are both located in the aircraft. The image processor converts the millimeter wave signals to millimeter wave images of the landing site to assist the pilot in landing the aircraft.
FIG. 1 shows a diagram of a conventional airborne millimeter wave imaging system. The aircraft 2 follows a flight path 16 towards runway 10. In the nose of the aircraft is a millimeter wave imaging system that includes a transceiver 4 and image processor 6. Transceiver 4 transmits millimeter wave radar signals that obtain images of the airport. The return signals, with a field of view 8, are processed by image processor 6. Image processor 6 is operationally connected to transceiver 4, and forms an image of runway 10 and taxiway 12 from the received signals. This image is provided to the pilot to aid in landing the aircraft in poor visibility conditions.
An important metric of a millimeter wave imaging system is its image quality. Generally, transceivers that exist onboard aircraft are heavy, bulky, and do not have the capability to perform the sophisticated processing that is required to enhance the image quality and improve the contrast of the landing site image viewed by the pilot. The transceiver is normally mounted in the nose of the aircraft in conjunction with other aircraft instruments. Therefore, retrofitting an aircraft to accommodate the transceiver volume can be difficult.
Further, many airborne millimeter wave imaging systems may have low signal-to-noise ratios further adding to decreased image quality. The signal-to-noise ratio may be improved if the time to capture the landing site image (dwell time) is increased. However, in airborne millimeter wave imaging systems, the aircraft has only a small amount of time to gather the image, process the image, and present it to the pilot so that the processed image can be used to aid in landing the aircraft.
In most aircraft, the weight of instruments and other items that are on board during flight is always a concern. The heavy, bulky transceivers and corresponding imaging processor that currently exist in airborne millimeter wave imaging systems add weight to the aircraft. Moreover, the addition of an airborne transceiver and associated imaging processor increase the overall cost of the aircraft.
In conventional airborne millimeter wave imaging systems, if the transceiver or the imaging processor develops a problem, or for some reason do not operate properly, the pilot will be without the aid of an imaging system. Due to space and size restrictions on the aircraft, there is usually no room to have a backup millimeter wave imaging system on the aircraft that can be used if the primary imaging system fails. Therefore, most conventional airborne millimeter wave imaging systems are limited in their ability to provide images to a pilot during faulty conditions in the airborne millimeter wave imaging system. Further, the addition of a backup millimeter wave imaging system on board the aircraft, if possible, further increases the cost of the aircraft.
Accordingly, the present invention is directed to a ground based millimeter wave imaging system that substantially obviates one or more of the problems arising from the limitations and disadvantages of the related art.
It is an object of the present invention to provide a ground based millimeter wave imaging system that provides increased image quality in the form of high contrast and high resolution.
It is a further object of the present invention to provide a ground based millimeter wave imaging system that increases the capability to perform sophisticated image processing algorithms.
Another object of the present invention is to provide a ground based millimeter wave imaging system that provides improved reliability of the overall landing system.
Still another object of the present invention is provide a ground based millimeter wave imaging system that reduces the weight, volume, and cost of a flight unit.
Accordingly, one aspect of the present invention is directed to a ground based millimeter wave imaging system that provides real-time millimeter wave images of an airport to one or more aircraft from one or more ground stations. The system includes at least one millimeter wave transceiver that is located in each, one or more, ground stations. Each, millimeter wave transceiver collects real-time millimeter wave images of the airport. At least one image processor is operatively connected to the millimeter wave transceiver and located in each ground station, and processes the real-time millimeter wave images of the airport. At least one data link allows communication of information between the one or more aircraft and the one or more ground stations. The ground stations transmit the processed real-time millimeter wave images to the aircraft using the data link.
According to another aspect of the present invention, the real-time millimeter wave images of the airport includes runways and taxiways at the airport.
According to yet another aspect of the present invention, the one or more ground stations obtain location and attitude information of at least one aircraft.
In a further aspect of the present invention, the location information of the one or more aircraft is obtained simultaneously with the collection of real-time millimeter wave images of the airport.
According to another aspect of the present invention, the ground stations obtain location information and attitude of one or more aircraft from the aircraft.
According to yet another aspect of the present invention, one or more ground stations obtain location information and attitude of one or more aircraft using a ranging radar located in one or more ground stations.
In a further aspect of the present invention, the location information includes coordinates and attitude of the one or more aircraft.
According to another aspect of the present invention, the data link may be a high-speed full duplex data link.
According to yet another aspect of the present invention, one or more ground stations converts the processed millimeter wave images of the airport to a format suitable for viewing by pilots of one or more aircraft.
In a further aspect of the present invention, each ground station communicates information about the millimeter wave images of the airport to each other.
Another aspect of the present invention is directed to a method for providing real-time millimeter wave images of an airport to at least one aircraft to aid in landing and taxiing of the aircraft. Real-time millimeter wave images are collected of the airport by at least one ground station. Location and attitude information may be acquired for at least one aircraft. The millimeter wave images are processed where the processing occurs in at least one ground station. The processed millimeter wave images are in a format for viewing by a pilot of at least one aircraft. The processed millimeter wave images are transmitted to at least one aircraft.
According to yet another aspect of the present invention, the real-time millimeter wave images include images of runways and taxiways of the airport.
In a further aspect of the present invention, the location information includes coordinates and attitude of at least one aircraft.
According to another aspect of the present invention, each ground station communicates information about the airport to each other.
In a further aspect of the present invention, the location information for the at least one aircraft is acquired simultaneously with the collecting of real-time millimeter wave images of the airport.
According to another aspect of the present invention, the location information and attitude for the at least one aircraft is acquired from the aircraft.
According to yet another aspect of the present invention, the location information and attitude for at least one aircraft is acquired using a ranging radar located in at least one ground station.
In a further aspect of the present invention, the processed millimeter wave images are transmitted to at least one aircraft using a high speed full duplex data link.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawings.